(CBS/AP) STOCKTON, Calif. - A marriage counselor who specialized in anger management allegedly killed his ex-wife, her sister, and her aunt before turning his gun on himself inside a nursing home Monday, reports CBS Sacramento.

The killings took place at multiple locations in Stockton, Calif., including a senior assisted living center, said police.

According to CBS Sacramento, police received a call reporting a shooting at a Stockton home at 3:05 p.m. on Monday. When they arrived, they found 64-year Kathleen Arata dead from a gunshot wound. Witnesses described the suspect, Colin McGrattan, and his silver minivan, to police.

While investigating the shooting, police received a call of another shooting at an area senior assisted living center. There, they saw a van matching the suspect's vehicle parked outside, the station reports.

Inside a room at the residence, police found Chizuko Kaneishi, 88, with a gunshot wound. They also found McGrattan, 45, dead with a self-inflicted gunshot wound. A .38 special handgun was laying nearby.

Inside the van, police found the body of McGrattan's ex-wife, Jacklyn Arata, 57, wrapped in a tarp. She had been shot.

Police say Kathleen was Jacklyn's sister and Kaneishi, who was pronounced dead at the hospital, was their aunt.

Homicide investigators are exploring a financial motive for the killings.

"As long as I've known him, he's been very kind," said McGrattan's roommate, Courtney Bradford. "He was talking to me a lot about losing his home and bankruptcy and the money, lawyer for all the divorce court stuff."

McGrattan was a marriage counselor in Stockton. His website says he specialized in anger management and family issues. He and Jacklyn Arata had two sons.

"The other night he was talking about how upset he was about them not wanting to come visit his family for Christmas," Bradford said.

Police continue to investigate what led the suspected killer to go after not only his ex-wife, but her 64 and 88-year-old relatives.

"Investigators are talking to people who knew the suspect to see what he was going through," Silva said. "Maybe he told someone else the hardships he may have been having."

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